The Evolution of the Metcalfa Pruinosa, Nezara Viridula and Halyomorpha Halys Species Since the First Reporting in Agroecosystems in Romania

Abstract

After more years since the first notification, the following species of pests Metcalfa pruinosa, Nezara viridula and Halyomorpha halys are still present in agroecosystems in Romania. The high polyphagism, the easy adaptability to new areas and host plant species as well as the lack of a well-defined strategy to fight are characteristics that have contributed to maintaining an active population that still produces damage. Through the present paper, we have proposed to bring attention to their evolution since their first signalling on various plant species from various agroecosystems. We also focused on the current analysis of the numerical level of the active and inactive stages and the damages produced in agricultural and horticultural crops in the west of the country, in period 2020-2022. As a result of the evolution study, it was found that all 3 targeted species are still present on a large number of plant species from agro-horticultural crops composition (both in open or closed spaces). The active (nymphs and adults) and inactive (eggs) stages were observed on the analysed plants and their level was high especially in the species of M. pruinosa and H. halys, while the species of N. viridula species, registered a slight decrease. Thus, the damages produced were commensurate with the numerical level. Continuous monitoring of these highly agile polyphagous pests is necessary to prevent the gradual increase in populations in public places (parks) and the extension to plants in agroecosystems.